The expression of proteins in bacterial cell free synthesis systems is a well established technique for expressing recombinant target proteins. Extracts can be made from bacteria expressing or overexpressing proteins of interest to provide bacterial cell free synthesis systems having altered properties depending on the protein. However, overexpression of proteins during bacterial growth frequently results in slower growth rates for the bacteria and lower protein synthetic activity in extracts prepared from the bacteria.
This invention provides for high growth capacity strains of auxotrophic Escherichia coli. These strains find use in cell free synthesis systems where ribosomal density, as reflected by high growth capacity, is an economically important property of desired bacteria. The ability of bacteria to maintain high growth capacity after recombinant inactivation of enzymes is unpredictable.